The present invention relates to a steering wheel equipped with an airbag device operative to protect a vehicle driver at a vehicle crash. In particular, the present invention belongs to technology of a specific structure in which an operational portion to operate a vehicle on-board device or the like is provided at a pad portion of the steering wheel.
Conventionally, it is known that the airbag device is provided at the steering wheel to properly reduce an impact that the driver receives at the vehicle crash. Herein, the airbag device is provided in the pad portion of the steering wheel and it inflates an airbag cushion toward the driver when the crash is detected.
It is also known that at the pad portion of the steering wheel equipped with the airbag device are provided an operational portion to operate a vehicle on-board device, such as a horn switch, and/or an indicator of a liquid crystal panel, and that the airbag cushion is disposed so as to be inflated avoiding the operational portion and like. For example, U.S. patent application Publication No. 2002/0135163 A1 discloses the steering wheel in which the airbag cushion is accommodated in a ring shape around the center of the pad portion where the above-described operational device and the like are provided. Herein, at the pad portion are formed some tear lines extending in the radial direction from the center, so that a cover portion of the pad portion can open along the tear lines when the airbag cushion is inflated, leaving the center portion, which constitutes a fixed portion of the pad portion (hereinafter, this airbag is also referred to as a doughnut-shape airbag).
In the steering wheel equipped with such a doughnut-shape airbag, the center portion of the pad portion does not open as the fixed portion, where the above-described operational portion and the like are provided, when the airbag cushion is inflated. Accordingly, the airbag cushion is inflated, avoiding the liquid crystal panel disclosed in the above-described publication or the horn switch disclosed in Japanese Patent Application Laid-Open No. 2004-224145, and thereby the proper inflation of the airbag cushion can be endured and the switch and the like can be prevented from interfering with the driver during the inflation of the airbag cushion.
Meanwhile, it is also known that at the pad portion of the steering wheel are provided an emblem of automotive vehicle makers or the like and that the emblem is constituted so as to be illuminated to improve ornamental function and advertising function (see Japanese Patent Application Laid-Open No. 2000-118320, for example).
Herein, in the case where the above-described doughnut-shape airbag is provided and at the fixed portion of the pad portion of the steering wheel are provided the horn switch or the like, the operational function of such switches can be improved. However, since the driver's eyes tend to be turned downward, the visible function of the switches seems not necessarily appropriate. In particular, it would be difficult for the driver to properly conduct the operation of switches in case of emergency at night.